diff --git a/firmware/drivers/lcd.c b/firmware/drivers/lcd.c
index d0e2c623de..f33e8e5f2a 100644
--- a/firmware/drivers/lcd.c
+++ b/firmware/drivers/lcd.c
@@ -329,24 +329,24 @@ static const unsigned char lcd_ascii[] = {
 void lcd_clear_display(void)
 {
     int i;
-    lcd_write(TRUE,LCD_CURSOR(0,0));
+    lcd_write(true,LCD_CURSOR(0,0));
     for (i=0;i<24;i++)
-        lcd_write(FALSE,0);
+        lcd_write(false,0);
 }
 
 void lcd_puts(int x, int y, char *string)
 {
-    lcd_write(TRUE,LCD_CURSOR(x,y));
+    lcd_write(true,LCD_CURSOR(x,y));
     while (*string)
-        lcd_write(FALSE,LCD_ASCII(*string++));
+        lcd_write(false,LCD_ASCII(*string++));
 }
 
 void lcd_define_pattern (int which,char *pattern,int length)
 {
     int i;
-    lcd_write(TRUE,LCD_PRAM|which);
+    lcd_write(true,LCD_PRAM|which);
     for (i=0;i<length;i++)
-	lcd_write(FALSE,pattern[i]);
+	lcd_write(false,pattern[i]);
 }
 #endif
 
@@ -407,13 +407,13 @@ void lcd_init (void)
     PBIOR |= 0x000f; /* IOR = 1 */
 
     /* Initialize LCD */
-    lcd_write (TRUE, LCD_CNTL_RESET);
-    lcd_write (TRUE, LCD_CNTL_POWER);
-    lcd_write (TRUE, LCD_CNTL_SEGREMAP);
-    lcd_write (TRUE, LCD_CNTL_OUTSCAN);
-    lcd_write (TRUE, LCD_CNTL_CONTRAST);
-    lcd_write (TRUE, 0x30); /* Contrast parameter */
-    lcd_write (TRUE, LCD_CNTL_DISPON);
+    lcd_write (true, LCD_CNTL_RESET);
+    lcd_write (true, LCD_CNTL_POWER);
+    lcd_write (true, LCD_CNTL_SEGREMAP);
+    lcd_write (true, LCD_CNTL_OUTSCAN);
+    lcd_write (true, LCD_CNTL_CONTRAST);
+    lcd_write (true, 0x30); /* Contrast parameter */
+    lcd_write (true, LCD_CNTL_DISPON);
 
     lcd_clear_display();
     lcd_update();
@@ -430,12 +430,12 @@ void lcd_update (void)
     /* Copy display bitmap to hardware */
     for (y = 0; y < LCD_HEIGHT/8; y++)
     {
-        lcd_write (TRUE, LCD_CNTL_PAGE | (y & 0xf));
-        lcd_write (TRUE, LCD_CNTL_HIGHCOL);
-        lcd_write (TRUE, LCD_CNTL_LOWCOL);
+        lcd_write (true, LCD_CNTL_PAGE | (y & 0xf));
+        lcd_write (true, LCD_CNTL_HIGHCOL);
+        lcd_write (true, LCD_CNTL_LOWCOL);
 
         for (x = 0; x < LCD_WIDTH; x++)
-            lcd_write (FALSE, display[x][y]);
+            lcd_write (false, display[x][y]);
     }
 }
 
@@ -505,8 +505,8 @@ void lcd_putsxy(int x, int y, char *str, int thisfont)
             else
                 src = char_gen_6x8[ch-ASCII_MIN][0];
 
-            lcd_bitmap (src, lcd_x, lcd_y, nx-1, ny, TRUE);
-            lcd_bitmap (zeros, lcd_x+nx-1, lcd_y, 1, ny, TRUE);
+            lcd_bitmap (src, lcd_x, lcd_y, nx-1, ny, true);
+            lcd_bitmap (zeros, lcd_x+nx-1, lcd_y, 1, ny, true);
 
             lcd_x += nx;
         }
@@ -515,7 +515,7 @@ void lcd_putsxy(int x, int y, char *str, int thisfont)
 
 /*
  * Display a bitmap at (x, y), size (nx, ny)
- * clear is TRUE to clear destination area first
+ * clear is true to clear destination area first
  */
 void lcd_bitmap (unsigned char *src, int x, int y, int nx, int ny,
                  bool clear)
@@ -593,7 +593,7 @@ void lcd_clearrect (int x, int y, int nx, int ny)
 {
     int i;
     for (i = 0; i < nx; i++)
-        lcd_bitmap (zeros, x+i, y, 1, ny, TRUE);
+        lcd_bitmap (zeros, x+i, y, 1, ny, true);
 }
 
 /*
@@ -603,7 +603,7 @@ void lcd_fillrect (int x, int y, int nx, int ny)
 {
     int i;
     for (i = 0; i < nx; i++)
-        lcd_bitmap (ones, x+i, y, 1, ny, TRUE);
+        lcd_bitmap (ones, x+i, y, 1, ny, true);
 }
 
 /* Invert a rectangular area at (x, y), size (nx, ny) */
@@ -611,7 +611,7 @@ void lcd_invertrect (int x, int y, int nx, int ny)
 {
     int i;
     for (i = 0; i < nx; i++)
-        lcd_bitmap (ones, x+i, y, 1, ny, FALSE);
+        lcd_bitmap (ones, x+i, y, 1, ny, false);
 }
 
 #define DRAW_PIXEL(x,y) display[x][y/8] |= (1<<(y&7))
diff --git a/uisimulator/app.c b/uisimulator/app.c
index 5c96ab8c43..c5149d8171 100644
--- a/uisimulator/app.c
+++ b/uisimulator/app.c
@@ -17,7 +17,6 @@
  *
  ****************************************************************************/
 
-#include "types.h"
 #include "lcd.h"
 #include "button.h"
 #include "kernel.h"
diff --git a/uisimulator/common/mpegplay.c b/uisimulator/common/mpegplay.c
index aaaddfa014..5ecfca9e97 100644
--- a/uisimulator/common/mpegplay.c
+++ b/uisimulator/common/mpegplay.c
@@ -26,7 +26,6 @@
 #include <string.h>
 #include <stdlib.h>
 #include <file.h>
-#include <types.h>
 #include <lcd.h>
 #include <button.h>
 #include "id3.h"
diff --git a/uisimulator/menu.c b/uisimulator/menu.c
index dcaa1f5fca..6a6b61e755 100644
--- a/uisimulator/menu.c
+++ b/uisimulator/menu.c
@@ -17,7 +17,6 @@
  *
  ****************************************************************************/
 
-#include "types.h"
 #include "lcd.h"
 #include "menu.h"
 
diff --git a/uisimulator/play.c b/uisimulator/play.c
index 3681a7e133..e93f17672e 100644
--- a/uisimulator/play.c
+++ b/uisimulator/play.c
@@ -20,10 +20,9 @@
 #include <string.h>
 #include <stdlib.h>
 
-#include <file.h>
-#include <types.h>
-#include <lcd.h>
-#include <button.h>
+#include "file.h"
+#include "lcd.h"
+#include "button.h"
 #include "kernel.h"
 #include "tree.h"
 #include "debug.h"
diff --git a/uisimulator/screensaver.c b/uisimulator/screensaver.c
index a85ccf965d..b8144478e2 100644
--- a/uisimulator/screensaver.c
+++ b/uisimulator/screensaver.c
@@ -20,7 +20,6 @@
 #ifdef HAVE_LCD_BITMAP
 
 #include "screensaver.h"
-#include "types.h"
 #include "lcd.h"
 #include "button.h"
 #include "kernel.h"
diff --git a/uisimulator/tetris.c b/uisimulator/tetris.c
index 8884fd8964..24090eb67e 100644
--- a/uisimulator/tetris.c
+++ b/uisimulator/tetris.c
@@ -20,8 +20,7 @@
  ****************************************************************************/
 
 #ifdef HAVE_LCD_BITMAP
-
-#include "types.h"
+#include <stdbool.h>
 #include "lcd.h"
 #include "button.h"
 #include "kernel.h"
@@ -121,7 +120,7 @@ void draw_frame(int fstart_x,int fstop_x,int fstart_y,int fstop_y)
     lcd_drawline(fstop_x, fstart_y, fstop_x, fstop_y);
 }
 
-void draw_block(int x,int y,int block,int frame,int clear)
+void draw_block(int x,int y,int block,int frame,bool clear)
 {
     int i;
     for(i=0;i < 4;i++) {
@@ -143,7 +142,7 @@ void to_virtual()
           (current_x+block_data[current_b][current_f][0][i])) = current_b+1;
 }
 
-int gameover()
+bool gameover()
 {
     int i;
     int frame, block, y, x;
@@ -162,14 +161,14 @@ int gameover()
             if(y+block_data[block][frame][1][i] < start_y)
             {
                 /* Game over ;) */
-                return TRUE;
+                return true;
             }
         }
     }
-    return FALSE;
+    return false;
 }
 
-int valid_position(int x,int y,int block,int frame)
+bool valid_position(int x,int y,int block,int frame)
 {
     int i;
     for(i=0;i < 4;i++)
@@ -179,8 +178,8 @@ int valid_position(int x,int y,int block,int frame)
             (x+block_data[block][frame][0][i] > max_x-1) ||
             (y+block_data[block][frame][1][i] < 0) || 
             (y+block_data[block][frame][1][i] > max_y-1))
-            return FALSE;
-    return TRUE;
+            return false;
+    return true;
 }
 
 void from_virtual()
@@ -207,10 +206,10 @@ void move_block(int x,int y,int f)
     }        
     if(valid_position(current_x+x,current_y+y,current_b,current_f))
     {
-        draw_block(current_x,current_y,current_b,last_frame,TRUE);
+        draw_block(current_x,current_y,current_b,last_frame,true);
         current_x += x;
         current_y += y;
-        draw_block(current_x,current_y,current_b,current_f,FALSE);
+        draw_block(current_x,current_y,current_b,current_f,false);
         lcd_update();
     }
     else
@@ -225,27 +224,28 @@ void new_block()
     current_y = 0;
     next_b = t_rand(blocks);
     next_f = t_rand(block_frames[next_b]);
-    draw_block(max_x+2,start_y-1,current_b,current_f,TRUE);
-    draw_block(max_x+2,start_y-1,next_b,next_f,FALSE);
+    draw_block(max_x+2,start_y-1,current_b,current_f,true);
+    draw_block(max_x+2,start_y-1,next_b,next_f,false);
     if(!valid_position(current_x,current_y,current_b,current_f))
     {
-        draw_block(current_x,current_y,current_b,current_f,FALSE);
+        draw_block(current_x,current_y,current_b,current_f,false);
         lcd_update();
     }
     else
-        draw_block(current_x,current_y,current_b,current_f,FALSE);
+        draw_block(current_x,current_y,current_b,current_f,false);
 }
 
 int check_lines()
 {
-    int x,y,line,i;
+    int x,y,i;
+    bool line;
     int lines = 0;
     for(y=0;y < max_y;y++)
     {
-        line = TRUE;
+        line = true;
         for(x=0;x < max_x;x++)
             if(virtual[y*max_x+x] == 0)
-                line = FALSE;
+                line = false;
         if(line)
         {
             lines++;
diff --git a/uisimulator/tree.c b/uisimulator/tree.c
index 0382547590..1941661bb7 100644
--- a/uisimulator/tree.c
+++ b/uisimulator/tree.c
@@ -19,24 +19,22 @@
 
 #include <string.h>
 #include <stdlib.h>
+#include <stdbool.h>
 
-#include <dir.h>
-#include <file.h>
-#include <types.h>
-#include <lcd.h>
-#include <button.h>
+#include "dir.h"
+#include "file.h"
+#include "lcd.h"
+#include "button.h"
 #include "kernel.h"
 #include "tree.h"
-
 #include "icons.h"
-
 #include "play.h"
 
 
 #define TREE_MAX_FILENAMELEN 128
 
 struct entry {
-  int file; /* TRUE if file, FALSE if dir */
+  int file; /* true if file, false if dir */
   char name[TREE_MAX_FILENAMELEN];
   int namelen;
 };
@@ -110,7 +108,7 @@ int static showdir(char *path, struct entry *buffer, int start,
         else
             icon_type=Folder;
         lcd_bitmap(bitmap_icons_6x8[icon_type], 6, MARGIN_Y+i*LINE_HEIGTH, 6, 
-                   8, TRUE);
+                   8, true);
 #endif
 
         if(len < TREE_MAX_LEN_DISPLAY)
@@ -177,13 +175,13 @@ bool dirbrowse(char *root)
         }
         switch(key) {
             case BUTTON_OFF:
-                return FALSE;
+                return false;
                 break;
 
             case BUTTON_LEFT:
                 i=strlen(currdir);
                 if (i==1) {
-                    return FALSE;
+                    return false;
                 }
                 else {
                     while (currdir[i-1]!='/')
@@ -286,5 +284,5 @@ bool dirbrowse(char *root)
         }
     }
 
-    return FALSE;
+    return false;
 }
diff --git a/uisimulator/x11/button-x11.c b/uisimulator/x11/button-x11.c
index dc077f03b1..c3afa4b42a 100644
--- a/uisimulator/x11/button-x11.c
+++ b/uisimulator/x11/button-x11.c
@@ -16,7 +16,6 @@
  * KIND, either express or implied.
  *
  ****************************************************************************/
-#include "types.h"
 #include "button.h"
 
 #include "X11/keysym.h"